Wiseco tech tips/article

[Wiseco]

Hey gang. I'm looking for ideas for what you would like to see for a tech article. Is there anything detailed or specific about pistons you would like to know/read? Compression ratios? Oversizes? Forging technology? I could also write something about clutches, cams, or crankshafts. Other ideas? Let me know. PM or post. Thanks in advance!?

[clamber]

I know nothing about anything so any articles would be helpful to me.

Im a little curious about oversize pistons and what they add and what is needed to accommodate them

I just got one of your piston kits for my CR250 and Im excited to learn how to install it.

[chadk66]

Hey gang. I'm looking for ideas for what you would like to see for a tech article. Is there anything detailed or specific about pistons you would like to know/read? Compression ratios? Oversizes? Forging technology? I could also write something about clutches, cams, or crankshafts. Other ideas? Let me know. PM or post. Thanks in advance!?

Clutch stuff would be great. Specifically how to remove slack in the engaging mechanism because of wear on those items, etc.

[Salsa]

Do you have a collection of articles now that we can view?

Don

[Garage_guy_chris]

Id love to know how to figure out needed fuel octane for a certain compression ratio both 4 and 2 stroke, Id love to raise compression on both bikes but i dont wanna do it trial and error, to expensive, i would love to know how to figure this out

[Wiseco]

Do you have a collection of articles now that we can view?

Don

Below are a few articles written on Wiseco's behalf. I could expand on any of these subjects, or pick something new based on your requests.

Fresh top end = cheap insurance!

https://www.thumpertalk.com/forum/showthread.php?t=716908

Basic clutch maintenance

https://www.thumpertalk.com/forum/showthread.php?t=230982

How to install an aftermarket clutch basket

https://www.thumpertalk.com/forum/showthread.php?t=232390

[babyarmholdingapple]

I already PM you once about expansion rates of the materials/alloys.

Felt like I got a canned answer.

I also have looked for a bottom end rebuild

kit for a KX 85. Back ordered. After really

looking hard I found out they were China

manufactured and some are recalled.

At this time I am about to walk away from your product line.

So what is the deal on the bottom ends?

What is the expansion rates compared to OEM

for the above mentioned bike.

[Wiseco]

I already PM you once about expansion rates of the materials/alloys.

Felt like I got a canned answer.

I also have looked for a bottom end rebuild

kit for a KX 85. Back ordered. After really

looking hard I found out they were China

manufactured and some are recalled.

At this time I am about to walk away from your product line.

So what is the deal on the bottom ends?

What is the expansion rates compared to OEM

for the above mentioned bike.

Wow - dropping some bombs on me. I will reply as best as I can. I remember our discussion about the drag marks on your KX85 piston, and I thought I gave you a pretty detailed explaination about the importance of proper warm up and ring end gaps, but I can't say much more than that without seeing your part and knowing more about the application. I am happy to elaborate if you need more info. I can say all Wiseco pistons are engineered for proper running clearance at operating temperature with proper warm up. Proper warm up means putting heat into the piston/cylinder by warming up the engine for a 1-2 minutes with light throttle blips before pinning the throttle and blazing down the trail. It's no more complicated than that, but some guys start their bikes, pin the throttle, and click it into gear. That is how cold seizures can occur. It is no different for cast OEM piston alloys, but different alloys have different CTE's, which require different cold clearance. Wiseco piston shapes and clearances (two different things) are designed for power and performance at operating temperature.

All Wiseco pistons and clutch components are forged and machined right here the USA. Every Wiseco product is engineered and tested at Wiseco, and does not get the stamp of approval without being high quality. It is true (like many other manufacturers in our industry) that not everything we sell is manufactured in the USA. Unfortunately in order to bring high quality products to the market at the prices the market demands, we can't make everything state side. I guess that holds true for lots of things these days.

Regarding the recall, there was a recall on a very narrow list of crank part numbers, that make up a very small number of parts in the field, and is the result of internal testing. Please contact Wiseco customer service for more information. I can say it is unrelated to any 2-strokes applications.

Please guys I didn't want to turn this thread into a Wiseco discussion and certainly not a debate of technical issues. I was just looking for ideas for tech/product article ideas. I am happy to help provide any information I can. Thanks for your feedback. ?

[aakmetz]

a detailed explanation of the drill for the exhaust bridge. its always brought up in threads here, and the instuctions supplied w/ the pistons aren't very detailed maybe a list of applications that must be drilled and or an example of what a exhaust bridge looks like. to clarify if your engine has one.

[Smacaroni]

Id love to know how to figure out needed fuel octane for a certain compression ratio both 4 and 2 stroke, Id love to raise compression on both bikes but i dont wanna do it trial and error, to expensive, i would love to know how to figure this out

This would be a good one, if there really is a mathematical explanation.

I've been wondering why the piston skirt on some machines is "normal" as in the same shape as a car - the skirt runs the complete circumference, some have a different shape, like a triangle shape cut out of them but still are pretty long and some have no skirt at all.

Also, the advantages of three rings vs. two. Smoke less? Better compression? Both? Other?

And is there a rhyme or reason to the way the underside of the piston is shaped? Not all look to be weight savings.

Last, how do you measure the piston to match the cyl. For instance my 90-something PW has a bore of 48.97mm, the closest size is a 49mm, but that's 0.03 mm over and would make a good press fit, but you don't want that kind of fit for a piston since it moves. But 48.5mm is gonna be sloppy. So does that mean it wasn't bored over right?

[babyarmholdingapple]

Not tring to drop a bomb but do have real concern of various issues.

I have used your product line for Jet Skis and Bikes for 30 years

and this is/was the first time I had a concern. While I understand

the warm up process and adhere to it this KX is newer to me. I

did the top end and you read my remarks, I am just grasping

what happened to this motor. I have since lost the bottom

end as well. I suspect 5 years of abuse and actually find this

to be a testiment of the quality of this motor; it took a beating.

I guess the Maxima web site has spoiled me and I use there

products because of the information they supply. This motor

will now become a 100cc and I was just looking a information.

The process is not cheap and the information is valuable.

I also put my money where my mouth is and tend to pay more

for parts produced in the USA or it's allies. I love Pistons from

Ohio, more then ones from Japan. At the same time a Japan

crank is better then a China and I assume I will get what I

pay for.

No hard feelings just want a motor that will last.

[Wiseco]

Thanks ossidog - agree and appreciate your comments. ?

[Ud_Luz]

There's been a lot of disagreement over forged versus cast. Information on the differences and the pros versus cons would be nice.

[Dirtymutt9]

^^^^^^ +1

There has been some interest in your "racers edge" line of 2 stroke pistons on these boards. I understand that they use a single ring piston. Virtually all of the individuals running the "racers edge" 2 stroke pistons also run your Ti coated ring.

I am curious what the benefits of the Ti ring are? i would assume longevity and better seal. but how and why? would it be a good idea to run the Ti rings on a standard Pro-lite piston to help maintain compression levels between topends?

Also, is there a cross reference for the "Racers edge" pistons for suzuki Rm250's? I cant seem to find them in your catalog's

[CRF150F_06]

I would like to know what do you change on a piston to give it a higher or lower compression ratio?

Is there a way to tell the compression ratio of a piston just by looking at it?

[VTNewb]

As a guy getting his masters in thermo/fluids, I want to know about new and wacky forging processes since I decided to leave materials behind!

Also: I sent a panic e-mail to you guys about a KTM 440 piston, and though you didn't have one you still sent it around the office and found me a contact. Excellent customer service and I'm impressed. ?

Unfortunately when I managed to locate one I was sent a KTM 550 piston instead. Whoops. Fortunately it's going on ebay now and has 12 bidders!

[Wiseco]

You guys are full of good questions!! Thanks for the feedback. I guess I need to get going on the tech articles.

Real quick on a few of your questions: Compression ratio is the ratio of the volume of air above the piston at bottom dead center to the volume of air at top dead center. Another way to think of it is how much the volume of air above the piston at bottom dead center is compressed when the piston reaches top dead center. For example, if the volume of air above the piston at bottom dead center is "10 units", and the volume of air above the piston at top dead center is "1 unit", the compression ratio is 10:1. If the stock compression is 10:1, we can add material to the top of the piston (while making sure it doesn't hit the head/valves). Adding material to the top of the piston takes up some of that air volume, and thus increases the ratio of air being compressed. That is it in simplest terms. I will see about putting more detailed information and real mathematical calculations using bore/stroke/dome volume/deck/gasket thickness etc in a dedicated tech article.

Racer's Choice pistons with TiN rings: (short version again) Our racer's choice 2-stroke parts are:

--single ring (for less weight and friction),

--hardcoat anodized (for wear resistance in pin bore and ring grooves, and elimination of ring "microwelding" in ring grooves)

--pinned on center (forgot the reason)

--full skirt (no side milling - seals up better and creates better compression)

--no intake port (for better mid-range and top end power)

All these features make these parts sort of the Cadillac of our 2-stroke line.

In addition, we offer titanium nitride (TiN) coated rings. TiN is a very thin and durable face coating with a low coefficient of friction. This of course reduces friction in the bore, but more importantly offers greatly increased wear resistance to the ring face. That means after hours of use, the barrel shape of the ring face remains (instead of wearing flat like on a chrome ring), which in turn continues to seal up very well. This all adds up to sustained power for a longer time, where a normal chrome faced ring would start to allow power loss. Keep in mind I am speaking in very general terms, but that is the technology involved. I can say the TiN rings are legit. Anyone that has run them can probably tell you it looked brand new after a LONG time, when they expected to see significant ring wear.

[1st4stroke41]

How about honing a plated cylinder or why some of the pictures of the pistons show coated skirts but when you buy them they come uncoated?

We honed the last one with an old 3 stone flex hone, it seemed to work fine.

[Dirtymutt9]

right on! thanks for the answers!!!!